The invention relates to a device based on single electromagnet suspension and air floatation compound supporting and a control method thereof, and belongs to the technical field of precision equipment. The device comprises a base, a shock insulation platform and the like. A compound electromagnet comprises a single electromagnet and industrial aviation aluminum I. The single electromagnet is wrapped with the industrial aviation aluminum I. A composite bearing comprises a single electromagnet and industrial aviation aluminum II. The single electromagnet 7-1 is wrapped with the industrial aviation aluminum II 7-2. The control method comprises the steps that the compound electromagnet and the composite bearing are powered at first to generate an air film I, then pressure is applied to the composite bearing through an air cylinder, the thickness of the air film I is controlled, finally, air is supplied to the composite bearing, the pressure applied by the air cylinder is adjusted properly, and a new air film II is formed between the compound electromagnet and the composite bearing. The air film I can meet the requirement of non-mechanical friction in the starting stage of the composite bearing 7, the thickness of the air film I is basically uniform, and thus damage of an air bearing caused by vibration in tests is effectively reduced. The device is simple in model, high in reliability and easy to realize.